Add extension packaging script with debug content filtering

[bastiensoret]

Summary

This PR adds a packaging workflow for the browser extension that creates a production-ready ZIP file while automatically filtering out debug content scripts from the manifest.

Key Changes

• Added --package flag support to the build script that:
  • Builds the extension in production mode
  • Removes debug.js from content scripts in the manifest
  • Creates a versioned ZIP file of the dist directory
• Modified manifest.json handling to parse and conditionally filter content scripts based on build mode
• Added npm run package script for easy extension packaging
• Debug script is now only copied to dist during development builds, not production builds

Implementation Details

• The build script now parses manifest.json as JSON to allow dynamic modification of content scripts
• In package mode, content scripts are filtered to exclude any referencing debug.js
• In development mode, the debug script is copied as before for local testing
• The packageExtension() function reads the version from the built manifest and creates a ZIP file named cesar-v{version}.zip
• Uses execSync to run the zip command from the dist directory

https://claude.ai/code/session_01NTwC9wd4hoTixpwU6SzPmP